I recently changed the credentials that my ASP.Net MVC application uses to invoke my TeamCity server via the REST API and I soon noticed a significant performance degradation, i.e. some pages that used to take a couple of seconds to load now take over a minute.
After investigating with further with a performance profiler I can see the bottleneck being the calls to TeamCity. Initially I thought the problem was with the TeamCity Server, but after changing the credentials back to the previous user name and password the performance is back to what it was.
After further investigation outside my application using the ARC tool I can see that making the same API call takes around 400ms with the old credentials and in excess of 7,000ms with the new credentials.
The only thing I can think that perhaps could affect this is the roles and groups of the two TeamCity users belong to, however I have made sure they are identical and I the performance differential is still the same.
I don't see any error related to these calls in the teamcity.rest log.
Does anyone have any advice for what else might be affecting this or how I can try to diagnose this further?